sometimes after I make a modificartion when it restart I see this but can not connect, when I restart the printer i can connect again.
I'm using:
Firmware Name: RepRapFirmware for Duet 2 WiFi/Ethernet
Firmware Electronics: Duet WiFi 1.02 or later
Firmware Version: 1.21RC5 (2018-03-16 build 1)
WiFi Server Version: 1.21RC5(16b1)
Web Interface Version: 1.21-RC4

This all start when one day I turned on and it did not connect
I had to use YAT and found that there was bo config,g file anymore.
after I copied the file from my pc it has been giving me problems.
As to why the file disappeared I have no idea as I had not made any changes in them at taht time.